Process for the treatment of textile materials



' 3, 1938. J. BRANDWOOD 2,127,638

PROCESS FOR THE TREATMENT OF TEXTILE MATERIALS Filed June 2, 1937 Msfiller? g:-

Patented Aug. '23, 1938 OFFICE PROCESS FOR THE TREATMEN OF TEX- TILEJoseph Brandwood', Southport, England ApplicationJune 2, 1937, SerialNo. 145,982

Great Britain June 9, 1938 3 Claims. '(OI. 28-58) In the textileindustries various textile yarns or threads are doubled together orcabled with a high degree of twist. As examples may be cited threads ofsilk or artificial silk which are creped,

5 and also heavy yarns for use in the preparation of tire fabrics oranalogous fabrics. The strain imparted to the yar'ns or threads duringthe twisting gives rise to a tendency of the complete yarns or threadsto crinkle or twist irregularly 10 when freed from the doubling ortwisting action. In the case of silk and artificial silk threads thistendency which I may refer to as liveliness has been corrected ornullified by treating the finished threads with steam, but conditions in16 which steam is permitted to condense unduly on such material shouldbe avoided. as such condensation is highly deleterious; and this refersto all fibrous yarns or threads to a greater or lesser degree.

20 Also in the case of woven or other interlaced fabrics of a compactnature, for example canvas ducks as used in the manufacture of drivingand other beltings, there is a tendency for the fabric to creep andbecome uneven .and irregular and 25 this appears to be due to strainsinherent in the component yarns or threads thereof and also in somecases to the tension necessarily applied with such yarns or threads inthe manufacture of a fabric, e. g., in weaving.

3 The present invention is directed to the provision of a very simplerapid and efficient method whereby the liveliness of yarns or threadsand the creeping. of fabrics, above referred to and all effects ofirregular'stresses and strains set 85 up in yarns or threads or fabricsas a result of their preparation, may be counteracted and the yarns orthreads or fabrics permanently set, that is to say flattened or deadenedso that these conditions will no longer exist, this being effected 40without damage to the material. To this end the invention consists insubjecting the textile material in a condition of partial vacuum to theaction of steam of a temperature higher than the boiling point of waterin the vacuum condi- 4 tion prevailing. The effect of the treatment isin effect a temporary plasticization of 'the material fibres whichserves for the permanent setting of the yarns or threads or fabrics.Very accurate control of the vacuum and steam heat 50 figures ispossible, and the required setting can be effected with the addition ofa minimum of moisture and without deleterious condensation upon thegoods, by breakage of the falling vacuum at a desired point.

56 The textile material may be in any form,

such as yarns or threads in cheeses or in hanks or skeins, and wovenfabrics for example in the form of rolls. A suitable apparatus forcarrying out the process is shown in the annexed drawing .zhich isschematic, and 5 such process, with comparative vacuum and steam heatfigures given by way of example, will now be described, reference beinghad to such drawing.

A cylindrical casing I of suitable metal is mounted upon bearingbrackets 2 of metal to a. desired number, this casing having a door 3with hinges 4 and 5 and a handle 6. The interior of the casingcommunicates with a vacuum pump I by a pipe 8 and valve 9, the latterbeing a valve which may be operated to open communication to atmosphereas required. By a pipe and valve II the interior of the casing I is putinto communication with a source of steam, notshown. A steam trap I2 isprovided so that as little water of condensation as possible may enterthe casing I when the valve II is open. A drain pipe I3 has thereon avalve I4 which may be a check valve, that is to say a. valve which willpermit outflow of any water of -condensation from the interior of thecasing I when the latter is at atmospheric pressure, but will preventaccess of air thereto when not desired. Shelves of wire mesh or otherformnot shown-may be fitted within the casing I to receive goods to betreated. In practice it is found sufllcient to have a lining of rubberor the like upon the front edge of the casing to secure airtightnesswhen the interior thereof is evacuated, but securing bolts may beprovided. Known forms of steam and vacuum gauges being fitted to thecasing, this completes a simple .assembly of apparatus for carrying outthe process by manual operation, and this will now be described. 40

The vacuum pump being started, the interior of the casing I is evacuatedto 28" of mercury column. When this figure is reached as shown on theindicator, the vacuum pump is stopped. The steam valve II is now openedand steam at a pressure of lbs. to the square inch as indicated on thepressure gauge is admitted to the casing I. For gradual admission of thesteam the end of the steam pipe Ill may terminate within the casing I inthe form of a nozzle of 50 desired cross-sectional area. Admission ofsteam continues until the degree of vacuum within the casing shows afall to a figure from 15" to 10" of mercury column, depending upon thenature of the goods being treated, that is to say until the desireddegree of plasticization of the same has been reached. The steam valve His then closed and the valve 9 operated to admit atmospheric air, theremaining vacuum in the casing being thus broken. The goods' are thenremoved.

With the degree of original vacuum indicated, viz: 28" of mercurycolumn, or 1 lb. pressure absolute, the boiling point of water in suchvacuum is approximately 102 degrees Fahrenheit. Saturated steam at 50lbs. per square inch, pressure gauge, has a temperature of approximately298 degrees Fahrenheit. It will be seen therefore that the treatmentcommences with a considerable heat reserve in the steam above theboiling point in the vacuum conditions prevailing, and due to thepresence of this heat reserve in the operation all the advantages ofsteam treatment in setting the textile material are obtained withoutinjurious condensation of steam thereon and without the risk .of damageto the said material, in particular, goods of artificial silk, whichwould result from the direct application thereto,

in atmosphere, of steam at the degree of temperature given.

- As will be understood, the figures given in the above example may bevaried as desired, so long as the basic principle is' observed, to wit,that the entering steam is at a temperature above the boiling point ofwater at the vacuum degree selected, and that the plasticization effectis attained upon the material, without undue condensation.

The vacuum pump may continue to exhaust the casing l throughout thetreatment with steam, the pump and the steam supply being stoppedtogether, if this is found desirable, and

the steam from the said casing may pass to the pump through or over acondenser of any form.

- operation of the steam valve II; and admission of atmospheric air, mayall be controlled and operated automatically by electrical means withthe use of a diaphragm switch or the like in the manner known in generalapplication for the periormance ota sequence of steps.

I claim:

1. Process. for the setting of twisted textile yarns or threads andfabrics. for the counteraction of strains set up therein in the courseof their preparation, which process consists in subjecting the textilematerials in a partial vacuum in a closed casing to gradually enteringsteam having a higher degree of temperature than the boiling point ofwater in the vacuum conditions prevailing and. thus having a heatreserve over such boiling point, and on completion of desired treatmentof the materials breaking the vacrum whilst the steam temperature is.still sufficiently high to prevent undue condensation of such steam uponthe material.

2. Process for the setting of twisted textile yarns or threads andfabrics, for the counteraction of strains set up therein "in the courseof their preparation, which process consists in subjecting the textilematerials in a partial vacuum in a closed casing to gradually enteringsteam having a higher degree of temperature than the boiling point ofwater in the vacuum conditions prevailing and thus having a heat reserveover such boiling point, and on completion of desired treatment of thematerials breaking the vacuum whilst a degree of steam. heat reservestill exists.

3. Process for the setting of twisted textile yarns or threads andfabrics for the counteraction of strains set up therein. in the courseof their preparation which process consists in charging the textilematerial in a closable casing, evacuatingthe said casing of air to 28"of mercury column, admitting steam thereto at a pressure of 50 lbs. persquare inch pressure gauge, and shutting oi the steam and breaking thefalling vacuum when it has reached -a figure, of 10"-15" mercury column.

JOSEPH BRANDWOOD.

